1. Field of the Invention
The present invention relates to a technique of correcting for vibrations of an image capturing apparatus using both optical and electronic vibration correction systems in the image capturing apparatus.
2. Description of the Related Art
Recently, as image capturing apparatuses become more compact and the magnification produced by optical systems become higher, vibration of the image capturing apparatus can greatly degrade the quality of a captured image. Various vibration correction functions have been proposed, which correct the blur of a captured image, arising from vibration of the imaging apparatus. A conventional vibration correction function mounted in an image capturing apparatus is known in which the correction method uses both optical and electronic vibration correction systems (see, for example, Japanese Patent No. 2803072).
Firstly, the optical vibration correction system detects vibrations of the image capturing apparatus, and drives a vibration correction optical system to cancel the detected vibrations, thereby correcting the vibrations so that object light incident on the image sensor always enters the same position on the image sensing surface. Then, the electronic vibration correction system ascertains the displacement between images to detect the remaining vibrations that cannot be corrected for by the optical vibration correction system. The electronic vibration correction system moves the image read region to cancel the ascertained displacement between images, correcting for the remaining, low frequency, vibrations. In this way, the image capturing apparatus can improve the correction ability using both optical and electronic vibration correction systems.
However, the known correction method using both optical and electronic vibration correction systems suffers the following problems. An angular velocity sensor used to detect the amount of vibration of the image capturing apparatus can detect high frequency vibrations with high precision. However, the angular velocity detection characteristic generally becomes poor at low frequencies, of 1 Hz or less. Furthermore, the electronic vibration correction system cannot correct vibrations during the accumulation period of time. When all remaining vibrations, which cannot be corrected for by the optical vibration correction system, are subjected to correction by the electronic vibration correction system based on detection of a blur between images, the image quality deteriorates owing to vibrations during the accumulation period of time due to the generation of large amplitude low frequency vibrations.